Reversible fuel pump for oil burners



Feb. 19, 1957 Filed Nov. 29, 1952 W. J. BANGS REVERSIBLE FUEL PUMP FOR OIL BURNERS 5 Sheets-Sheet 1 IN V EN TOR.

Feb. 19, 1957 w. J. BANGS ,781,726 I REVERSIBLE FUEL PUMP FOR OIL BURNERS Filed Nov. 29, 1952 5 She ets-Sheet 2 W #7 INVENTOR.

Feb. 19, 1957 w. J. BANGS 2,731,726

' REVERSIBLE FUEL PUMP FOR 011. BURNERS Filed Nov. 29, 1952 5 Sheets$heet 5 IN V EN -T 0R.

Feb. 19, 1957 w. J. BANGS 2,781,726

REVERSIBLE FUEL PUMP FOR OIL BURNERS Filed Nov. 29, 1952 5 Sheets-Sheet 4 Feb. 19, 1957 w. J. BANGS REVERSIBLE FUEL PUMP FOR on. BURNERS Fil ed Nov. 29, 1952 5 Sheets-Sheet 5 IN VEN TOR. if 75mg.

United States Patent REVERSIBLE FUEL PUlVIP FOR OIL BURNERS Walter J. Bangs, Chicago, Ill., assignor to Tuthill Pum Company, a corporation of Illinois Application November 29, 1952, Serial No. 323,262

1 Claim. (Cl. 1033) This invention relates to fuel pumps for oil burners, and has for its principal object to provide a pump that can be readily reversed to suit the installation, and is simple and easy to service.

Generally speaking, this is accomplished by providing a pump housing with inlet and outlet chambers and inlet and outlet passages connected with the respective chambers and mounting a pump assembly unit in the inlet chamber having laterally extending passages lapping said inlet and outlet passages whereby the pump unit may be turned about to maintain the direction of flow through said inlet and outlet passages upon reversal'of the direction of rotation.

Further objects and advantages of the invention will appear as the description is read in connection with the accompanying drawings, in which:

Fig. 1 is a side elevation of the fuel pump housing;

Fig. 2 is an end View of the same;

Fig. 3 is a vertical section on the line 3--3 of Fig. 1 with the pump elements removed;

Fig. 4 is a vertical, longitudinal section on the line 4-4 of Fig. 2; I

Fig. 5 is an enlarged view of the left end of Fig. 4;

Fig. 6 is a vertical transverse section on the line 6-6 of Fig. 1;

Fig. 7 is a vertical transverse section through the body of the pump housing on the line 77 of Fig. 5;

Fig. 8 is a transverse vertical section on the line 88 of Fig. 5, the strainer and strainer cover being removed;

Fig. 9 is a transverse vertical section on the line 9--9 of Fig. 5;

Fig. 10 is a transverse vertical section corresponding to Fig. 8 with the pump unit assembly reversed;

Fig. 11 is a section through the pump unit assembly, the shaft being shown in elevation;

Fig. 12 is a perspective view of the rotor housing and rotor housing bushing displaced from their assembled positions as shown in Fig. 11;

Figs. 13 and 14 are elevations of opposite sides of the pump unit cover plate;

Fig. 15 is an enlarged section on the line 15-15 of Fig. 14;

Fig. 16 is a diagram simulating a longitudinal vertical section along the axis of rotation with the several parts displaced in order to have them appear in a single plane;

Figs. 17 and 18 are sections through the pump housing body on the lines 17-17 and 1818, respectively, of Fig. 3.

But these specific illustrations and the corresponding description are used for the purpose of illustrative disclosure only, and are not intended to impose unnecessary limitations on the claim.

General description In Fig. 16, the fuel pump housing is indicated generally by 10 and shown composed of a body portion 11 and a strainer cover 12 providing an inlet chamber 13, an outlet chamber 14, and a by-pass chamber 15.

2,781,726 Patented Feb. 19, 1957 Between the inlet chamber 13 and the outlet chamber 14 the housing body has a wall or solid portion 16 provided with an inlet passage 17 and an outlet passage 18, the latter being extended by a drilled hole 19 leading to the outlet chamber 14.

Mounted on the wall 16 within the inlet chamber 13 is a pump unit assembly generally indicated by 20 and containing pumping gears generally indicated by 21.

Between those gears 21 and the face of the wall 16 there is a pump unit cover 22 having an inlet passage 23 receiving fuel from the inlet passage 17 and delivering to the gears of the pump and an outlet passage 24 receiving from the gears of the pump and delivering to the outlet passage 18.

The outlet chamber 14 delivers to the nozzle by suitable connection indicated by the arrow 25, and the pressure on the nozzle is regulated by an adjustable valve generally indicated by 26.

The excess in the regulating valve 26 goes into the bypass chamber 15, and thence through a drilled passage 27 to the inlet passage 17 in a one-pipe system or out of the casing as indicated by the arrow shown at outlet 28 to a tank in a two-pipe system.

Specific description The pump housing body 11 is provided in its upper portion with oppositely directed, threaded openings 30, one of which is used for the supply pipe leading from the oil tank, the other being for a vacuum gauge. The threaded inlet opening 30 leads into the right end of the inlet chamber 13 outside of the screen 31, which, as best shown in Fig. 5, extends between a shoulder 32 on the housing body and a spring washer 33 in the screen cover, where it is sealed by suitable gaskets. The inlet chamber 13 is sufliciently large to provide for ample screen area to meet the underwriters requirements for 5, 7, or 9 gallons per minute.

As here shown, the inlet passage 17 is a slot or groove in the face of the wall 16, as best shown in Fig. 3; and the outlet passage 18 is a similar slot or groove on the opposite side of the face of the wall communicating with the drilled outlet passage 19 leading to the outlet chamber 14;

The pump unit assembly (Fig. 11) includes a rotary shaft 34 for a driving gear 35 meshing with a driven gear 36, the two associated with a crescent 37 on a rotor housing bushing 38 pressed into a rotor housing 39 to which is secured a pump unit cover plate 22 by screws 41, the rotor housing, the rotor housing bushing, and pump unit cover forming a pump casing about the gears.

The pump unit cover plate 22 (Figs. l3, l4, and 15) has separate inlet and outlet passages 23 and 24, respectively, for the pump unit assembly. On the right side in Figs. 5, l4, and 15, those passages are extended by lateral or circumferential grooves 42 and 43 (Fig. 14), which overlap and communicate with the inlet passage 17 and the outlet passage 18 in the face of the wall 16 against which the pump unit cover plate is bolted.

On the left side of the pump unit cover plate 22 (Figs. 5, 13, and 15), the passages 23 and 24 are laterally or circumferentially extended by grooves 44 and 45, which communicate with the suction and pressure chambers in the pump unit assembly.

The inlet passage 17 should be subject to suction or reduced pressure at all operative times, and the outlet passage 18 should be subject to the pressure of the pump at the same times. However, when the direction of rotation of the shaft 34 and hence the gears 35 and 36 is changed, the suction and pressure chambers of the pump are reversed or interchanged. Hence, in order to have the correct suction and pressure of the pump, it is necessary to rotate the pump unit assembly to bring the inlet 23 and the outlet passage 24 of the pump into communi- 3 cation with the inlet and outlet passages 17 and 18 in the wall 16.

As here shown, the rotor housing 39 and the pump unit cover plate 22 are provided with bolt openings 46 for bolts 47 threaded into the pump body at 48. There are six threaded openings 48 in the pump body, three of which are used at a time for a corresponding number of bolts 47. When the direction of rotation of the shaft 34 is reversed, it is only necessary to remove three bolts 47, turn the pump unit assembly through 180 degrees about the axis of the shaft, and insert the bolts again.

During this rotary movement, the lateral or circumferential extensions 42 and 43 of the passages 23 and 24 establish the suction and pressure communication with the inlet and outlet passages 17 and 13, so that the inlet and outlet to and from the main pump housing remain in the same direction after the change of rotation of the shaft 34.

The outlet chamber 14 is relatively small and may be regarded as only an enlargement in the outlet passage. The body of the pump housing is provided with a vertical bore 50, which receives a valve sleeve or tube 51 seated against a gasket 52 and held in place by a cap 53 having a central threaded bore 54 for an adjusting screw 55 for compressing a spring 56 against a valve 57 including a piston 57a and a stem 57b cooperating with the valve seat 58 in a plug or nipple 59 having a threaded outlet 60 for piping leading to the nozzle.

By means of the adjusting screw 54, the pressure on the valve may be regulated to deliver whatever is required to the nozzle, the excess passing through openings 61 into the bypass chamber 15. The valve sleeve 51 is provided with an auxiliary passage 63 to equalize the pressure on the valve; and there is a leakage groove 64 in the valve to prevent chattering.

The by-pass passage 27 is drilled through the body of the pump housing from the by-pass chamber to the inlet passage '17. In a one-pipe system, this permits the excess liquid from the by-pass chamber 15 to return to the inlet side of the pump.

In a two-pipe system, the passage 27 is closed by a plug 65, and outlet 28 is the return to the tank.

The strainer cover 12 is threaded onto the housing body 11 and sealed by a circular, rubbery composition 67, circular in cross section, known in the trade as an O ring. Removing the strainer cover gives ready access to the strainer for cleaning and to the bolts 47 for rotating the pump unit assembly.

The valve cap 53 is also sealed by a gasket 68 known in the trade as an 0 ring.

The shaft 34 is journalled in bearings 69 in the housing body 11 and is provided with a liquid seal 70 which efiectively closes the bypass chamber 15.

I claim:

A fuel pump comprising a housing having inlet and outlet passages and including a main body portion, a shaft extending through said main body portion and projecting from one end only of the housing, a cap removably secured to the main body portion and sealing the opposite end of the housing, an internal-external gear pump unit mounted on the end of the shaft within the housing, a pump unit cover plate surrounding the shaft and affixed to the pump unit to form therewith a permanent assembly and having a pair of ports extending through said plate communicating respectively with the inlet and outlet sides of the pump unit, there being on each side of the plate a pair of arcuate grooves communicating with said ports, the grooves on the side of the plate adjacent to the pump unit extending in opposite directions toward each other from said ports and the grooves on the other side of the plate extending in the same direction away from the ports, so that rotation of the pump unit and cover plate assembly from a first position in the housing to a second position in the housing will place the groove which was in communication with the outlet passage in communication with the inlet passage and vice versa, and bolt means extending through said assembly into the main body portion of the housing and accessible for withdrawal and replacement on removal of the housing cap for securing the assembly in either of said two positions.

References Cited in the file of this patent UNITED STATES PATENTS 2,107,152 Huber Feb. 1, 1938 2,246,610 Wagner June 24, 1941 2,628,567 De Lancey et al. Feb. 17, 1953 2,655,108 Osborne Oct. 13, 1953 2,665,636 Lauck et al Jan. 12, 1954 FOREIGN PATENTS 646,310 Great Britain Nov. 22, 1950 

